[PATCH] mtd: rawnand: Fix an error handling path in 'ebu_dma_start()'

[Christophe JAILLET]

If 'dmaengine_prep_slave_single()' fails, we must undo a previous
'dma_map_single()' call, as already done in all the other error handling
paths of this function.

Fixes: 0b1039f016e8 ("mtd: rawnand: Add NAND controller support on Intel LGM 
SoC")
Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
---
 drivers/mtd/nand/raw/intel-nand-controller.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/intel-nand-controller.c 
b/drivers/mtd/nand/raw/intel-nand-controller.c
index a304fda5d1fa..8b49fd56cf96 100644
--- a/drivers/mtd/nand/raw/intel-nand-controller.c
+++ b/drivers/mtd/nand/raw/intel-nand-controller.c
@@ -318,8 +318,10 @@ static int ebu_dma_start(struct ebu_nand_controller 
*ebu_host, u32 dir,
        }
 
        tx = dmaengine_prep_slave_single(chan, buf_dma, len, dir, flags);
-       if (!tx)
-               return -ENXIO;
+       if (!tx) {
+               ret = -ENXIO;
+               goto err_unmap;
+       }
 
        tx->callback = callback;
        tx->callback_param = ebu_host;
-- 
2.27.0